Transcript Feed Inputs to Animals

Feed Inputs to Animals
Bob von Bernuth
Considerations in a
Ration/Diet
Energy
Proteins & Amino Acids
Minerals
Vitamins
Non-nutritative additives
Energy
Energy is produced when organic
molecules undergo oxidation.
C6H12O6 + 6 O2 => 6 CO2 + 6 H2O +
energy
Proteins and Amino Acids
Proteins are amino acids
There are limiting amino acids
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Lysine
Methionine
A lot of others!
They should be balanced
Amino acids are the main source of N
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Limiting amino acids results in reducing N
excretion.
Animals generally have a dietary
requirement for
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Calcium
Chlorine
Copper
Iodine
Iron
Magnesium
Manganese
Phosphorus
Potassium
Selenium
Sodium
Sulfur
Zinc
Importance of Phosphorus
•
One of the most important minerals required
by livestock and poultry.
•
Complexes with calcium to give rigidity to
bones.
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An integral part of many organic compounds
– plays important roles in energy and protein
metabolism.
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Almost every biochemical reaction that
occurs in muscle, blood and other soft tissues
involves phosphorus.
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Affects protein synthesis, lean deposition in
growing animals.
Phosphorus Requirements
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Best source of unbiased information on
requirements is the nutrient requirement
publications of the National Research Council
(NRC).
NRC is part of the National Academy of
Sciences – a private organization established
140 years ago by President Abraham Lincoln to
advise the nation on issues of science and
technology.
The Committee on Animal Nutrition of the NRC
has established guidelines for feeding animals
for past 75 years.
Swine versus Dairy
Swine are a monogastric
Dairy cattle are ruminants
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Ruminants have a rumen (large stomach)
Rumen contains bacteria which produce
phytase enzyme—breaks down phytate
feedstuffs
Nonruminants don’t
Swine Considerations
Since they don’t have phytase—we
have to overfeed P in order to ensure
adequate available P.
Or—we can add phytase—it works in
swine, it just isn’t produced there (it
also works for poultry)
Or—we can use low phytate corn
Phosphorus
Essential for skeletal system
development
Generally low availability
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Feedstuffs—60-75% is phytate (not
available)
 Corn grain—14%
 Soybean meal—23-30%
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What happens to the rest?
Nitrogen and Phosphorus in
Animal Manures
N
Manure from:
Swine
Poultry
Beef
Dairy
Sheep
Sweeten (1992).
P
(% of DM)
4.71
5.13
3.96
3.75
3.89
2.97
1.62
1.07
0.79
0.56
Swine and Poultry Manure High in
Phosphorus - Why?
• Diets (especially swine diets) generally
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tend to be oversupplemented with
phosphorus.
Grains, oilseed meals in swine and poultry
diets are high in phytate phosphorus.
Pigs and poultry are unable to degrade
phytase and utilize the phosphorus - no
phytase in their digestive tract.
As a result, most of dietary phosphorus
from the natural ingredients is excreted in
the feces.
Phytic Acid – The Culprit
O
P
O
O-
-
O
P
O
O
O-
-
O
Phytate Phosphorus
O
P
O
O-
-
O
P
O
O
O-
-
O
Phytate Phosphorus Content of Cereal
Grains, Byproducts, and Oilseed Meals
Phytate Phosphorus
% of total P
% of total P
Barley
Oats
Corn
Wheat
Grain sorghum
Nelson et al. (1968).
56
56
66
67
68
Wheat bran
70
Wheat middlings 74
Soybean meal
61
Cottonseed meal 70
Sesame meal
81
Nutritional Strategies to Reduce
Phosphorus in Swine Manure
• Feed diets that are not excessive in
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phosphorus.
Formulate diets on an “available
phosphorus” basis.
Use feedstuffs that are low in phytate or
that have endogenous phytase.
• Wheat, wheat byproducts, triticale, barley.
Reduce dietary phosphorus and
supplement with phytase.
Use low-phytate cereals and oilseed
meals.
Model-Predicted P Excretion (kg) in
Growing-Finishing Pig Fed Corn-Soy Diet
from 20 to 120 kg
Kilograms of P
1.2
1.0
79% More P
Excreted
1.25
0.8
0.6
0.70
0.4
0.2
0.0
NRC (1998)
+ 0.2% Extra P
Phytase – What Does it Do?
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Increases phytate digestibility - increases
bioavailability of P in cereal grains and
oilseed meals.
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Reduces the amount of supplemental
inorganic P needed to maximize growth and
bone mineralization.
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Markedly reduces fecal P excretion.
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Increases the absorption of Ca, Mg, Zn, and
other divalent cations.
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May improve the utilization of dietary protein
Low-Phytate Corn
Forms of Phosphorus in Germ of Normal
and Mutant lpa1 Corn
0.5
P in germ, %
0.4
Other Organic P
0.3
Inorganic P
0.2
Phytic Acid P
0.1
0
Normal
Raboy et al. (1990)
Mutant lpa1
Soluble Carbohydrates in Soybean
UDP
Sucrose
UDP-Glu
UDP-Gal
Myo-Inositol
ADP
1
Sucrose
2
Fructose
Glucose
+
Fructose
UDP
3
1
Glu6P
ATP
2
Myo-Inositol, 1P
Synthase
Galactinol Synthase
3
Raffinose Synthase
4
Stachyose Synthase
Galactinol
Myo-Inositol
Phytic
Acid
Raffinose
Galactinol
4
Myo-Inositol
Stachyose
Dairy Considerations
A dairy cow has phytase. Perhaps
because of the large amount of feed
she eats (50-60 lb/day) some phytase
might help.
However, we tend to overfeed P.
Why Do We Overfeed P?
Safety margin
Not needed
Increased milk yield
Doesn’t work
Hypophasphatemia
Doesn’t
help
Improves reproduction Data ???
P in feed unknown
No excuse
You Get Back What You Put
In!
P has no gaseous phase
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It can’t escape to the air
If you fed it, it’s in the animal, the milk or
the excretion.
If you manure sample doesn’t show it, you
better look for it.
Dairy Phosphorus Balance
90
Total Intake
Unavailable
Potentially Available
9
81
Truly Absorbed
Milk
63
29
34
9
+
18
+
34
=
61
Nutrients retained by animals
(Elemental)
Animal
N
P
K
Beef
0.016
0.007
0.002
Dairy
0.012
0.007
0.002
Pork
0.023
0.007
0.002
Layers
0.022
0.006
0.002
Broilers
0.026
0.006
0.002
Turkeys
0.021
0.006
0.002